Tissue fusion jaw angle improvement

ABSTRACT

A bipolar forceps for sealing tissue includes an end effector assembly having opposing first and second jaw members having a proximal end and a distal end. The jaw members are moveable relative to one another from a first spaced apart position to a second position in which the jaw members cooperate to grasp tissue. Each of the jaw members includes an electrode having an electrically conductive tissue sealing surface. An electrical energy source may be connected to the tissue sealing surfaces so that the sealing surfaces can conduct energy to tissue. Each electrode may be hingedly connected to the respective jaw member to promote parallel closure of the sealing surfaces against tissue between the jaw members.

BACKGROUND

1. Background

The present disclosure relates to electrosurgical forceps for assuringuniform sealing of tissue when performing electrosurgical procedures.More particularly, the present disclosure relates to open, laparoscopic,or endoscopic bipolar forceps that improve the uniformity of currentdistribution through tissue and create a seal having a substantiallyuniform tissue thickness, by improving parallelism of the electrodefaces of the bipolar forceps.

2. Technical Field

Forceps utilize mechanical action to constrict, grasp, dissect and/orclamp tissue. Electrosurgical forceps utilize both mechanical clampingaction and electrical energy to effect hemostasis by heating the tissueand blood vessels. By controlling the intensity, frequency and durationof the electrosurgical energy applied through jaw members to the tissue,the surgeon can coagulate, cauterize and/or seal tissue.

In order to effect a proper seal with larger vessels or thick tissue,two predominant mechanical parameters must be accurately controlled—thepressure applied to the tissue and the gap distance between theelectrodes. As can be appreciated, both of these parameters are affectedby thickness of vessels or tissue. More particularly, accurateapplication of pressure is important for several reasons: to oppose thewalls of the vessels; to reduce the tissue impedance to a low enoughvalue that allows enough electrosurgical energy through the tissue; toovercome the forces of expansion during tissue heating; and tocontribute to the end tissue thickness which is an indication of a goodseal. It has been determined that a fused vessel wall is optimum between0.001 and 0.006 inches. Below this range, the seal may shred or tear andabove this range the lumens may not be properly or effectively sealed.

With respect to smaller vessels, the pressure applied to the tissuetends to become less relevant whereas the gap distance between theelectrically conductive tissue sealing surfaces becomes more significantfor effective sealing. In other words, the chances of two electricallyconductive sealing surfaces touching during activation increases as thevessels become smaller.

Electrosurgical methods may be able to seal larger vessels using anappropriate electrosurgical power curve, coupled with an instrumentcapable of applying a large closure force to the vessel walls. It isthought that the process of coagulating small vessels is fundamentallydifferent than electrosurgical tissue vessel sealing. For the purposesherein “coagulation” is defined as a process of desiccating tissuewherein the tissue cells are ruptured and dried and vessel sealing isdefined as the process of liquefying the collagen in the tissue so thatit reforms into a fused mass. Thus, coagulation of small vessels issufficient to permanently close them. Larger vessels need to be sealedto assure permanent closure.

Numerous bipolar electrosurgical forceps have been proposed in the pastfor various surgical procedures. However, some of these designs may notprovide uniformly reproducible pressure to the blood vessel and mayresult in an ineffective or non-uniform seal. Complicating mattersfurther is the fact that a non-uniform pressure applied to a bloodvessel creates varying tissue thickness along the length of the forceps.The result is varying pressure being applied, varying tissue thickness,and varying amount of electrosurgical energy passing through the tissue.All of these conditions reduce the effectiveness of the seal

SUMMARY

A bipolar forceps for sealing tissue includes an end effector assemblyhaving opposing first and second jaw members each having a proximal endand a distal end. The jaw members are moveable relative to one anotherfrom a first spaced apart position to a second position wherein the jawmembers cooperate to grasp tissue.

Each of the jaw members includes an electrode having an electricallyconductive tissue sealing surface. An electrical energy source may beconnected to the tissue sealing surfaces so that the sealing surfacescan conduct energy to tissue. The tissue sealing surfaces may include atleast one electrically non-conductive insulating member disposed thereonto prevent shorting between the sealing surfaces. The insulating membermay also be an insulating ridge disposed along a length of the tissuesealing surface.

In one embodiment, one or both electrodes may be hingedly connected to arespective jaw member at distal ends thereof to promote parallel closureof the respective electrically conductive tissue sealing surfacesagainst tissue disposed between the jaw members. The electrodes may behingedly connected to the jaw members at a distal end of the electrode.

The electrodes are hingedly connected to their respective jaw member bya resilient member. In embodiments, the resilient member is a piece ofspring metal.

In embodiments, a recess is defined in at least one of the jaws.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are described herein withreference to the drawings wherein:

FIG. 1 is a perspective view of an electrosurgical forceps in accordancewith an embodiment of the present disclosure;

FIG. 2A is a side view of a pair jaw members including individuallypivoting electrodes pivotally connected thereto in a first spaced apartposition in accordance with the present disclosure;

FIG. 2B is a side view of the jaw members in a second grasping tissueposition in accordance with the present disclosure;

FIG. 2C is a side view of the jaw members including an insulating memberdisposed on each tissue sealing surface of each electrode, the jawmembers being disposed in the first position in accordance with anotherembodiment of the present disclosure;

FIG. 2D is a side view of the jaw members of FIG. 2C in the secondposition in accordance with the present disclosure;

FIG. 3A is a side view of the jaw members including a wedge shapedelectrode disposed at a distal end of each jaw member in accordance withanother embodiment of the present disclosure;

FIG. 3B is a side view of the jaw members of FIG. 3A shown in the secondgrasping position;

FIG. 3C is a side view of the jaw members including an insulating memberdisposed on each tissue sealing surface of each electrode the jawmembers being disposed in the first position in accordance with anotherembodiment the present disclosure;

FIG. 3D is a side view of the jaw members of FIG. 3C in the secondposition in accordance with the present disclosure;

FIG. 4A is a side view of jaw members having opposing electrodes thereofpivotally connected at the distal end and connected by a spring at theproximal end, in accordance with the present disclosure;

FIG. 4B is a side view of the jaw members of FIG. 4A in the secondgrasping position in accordance with the present disclosure;

FIG. 4C is a side view of the jaw members including an insulating memberdisposed on each tissue sealing surface of each electrode, in the firstposition in accordance with another embodiment of the presentdisclosure;

FIG. 4D is a side view of the jaw members of FIG. 4C in the secondposition in accordance with the present disclosure;

FIG. 5A is a side view of a pair of jaw members connected by atrapezoidal pivot mechanism including electrodes disposed at a distalend thereof and shown in an open, spaced apart position;

FIG. 5B is a side view of the jaw members of FIG. 6A having aninsulating member disposed on each of the tissue sealing surfaces of theelectrodes;

FIG. 5C is a side view of the jaw members of FIG. 5A shown in the secondgrasping position;

FIG. 5D is a side view of the jaw members of FIG. 5B shown in the secondposition;

FIG. 6A is a side view of jaw members having opposing electrodeshingedly connected at the distal ends thereof in accordance with thepresent disclosure;

FIG. 6B is a side view of the jaw member of FIG. 6A shown in the secondposition grasping thick tissue;

FIG. 6C is a side view of the jaw member of FIG. 6A shown in the secondposition grasping thin tissue;

FIG. 7A is a side view of jaw members having a recess disposed thereinand opposing electrodes hingedly connected at distal ends thereof inaccordance with the present disclosure;

FIG. 7B is a side view of the jaw members of FIG. 7A shown in the secondposition grasping thick tissue; and

FIG. 7C is a side view of the jaw members of FIG. 7A shown in the secondposition grasping thin tissue.

DETAILED DESCRIPTION

Various embodiments of the present disclosure are described hereinbelowwith reference to the accompanying drawings. Well-known functions orconstructions are not described in detail to avoid obscuring the presentdisclosure in unnecessary detail. Those skilled in the art willunderstand that the present disclosure may be adapted for use with alaparoscopic instrument, an endoscopic instrument, or an openinstrument; however, different electrical and mechanical connections andconsiderations may apply to each particular type of instrument. Thenovel aspects with respect to vessel and tissue sealing are generallyconsistent with respect to the open, laparoscopic, and endoscopicdesigns. In the drawings and in the description that follows, the term“proximal”, as is traditional, will refer to the end of the forceps thatis closer to the user, while the term “distal” will refer to the end ofthe forceps that is further from the user.

Referring now to FIG. 1, a bipolar electrosurgical forceps according toan embodiment of the present disclosure is shown includingelectrosurgical forceps 10 configured to support end effector assembly100. Forceps 10 typically includes various conventional features (e.g.,a housing 20, a handle assembly 30, a rotating assembly 80, a triggerassembly 70, etc.) that enable forceps 10 and end effector assembly 100to mutually cooperate to grasp, seal and, if warranted, divide tissue.Forceps 10 generally includes housing 20 and handle assembly 30 thatincludes moveable handle 40 and handle 50 which is integral with housing20. Handle 40 is moveable relative to handle 50 to actuate end effectorassembly 100 to grasp and treat tissue. Forceps 10 also includes shaft12 that has distal end 14 that mechanically engages end effectorassembly 100 and proximal end 16 that mechanically engages housing 20proximate rotating assembly 80 disposed at the distal end of housing 20.Rotating assembly 80 is mechanically associated with shaft 12. Movementof rotating assembly 80 imparts similar rotational movements to shaft 12which, in turn, rotates end effector assembly 100. Forceps 10 alsoincludes an electrical interface or plug 300 joined to the forceps 10 byan electrosurgical cable 310 to connect the forceps 10 to a source ofelectrosurgical energy (not shown).

As explained in more detail below, with respect to FIGS. 2A-2D, endeffector assembly 100 includes jaw members 110 and 120 having proximalends 111 a, 121 a and distal ends 111 b, 121 b. Jaw members 110 and 120are moveable from a first position wherein jaw members 110 and 120 arespaced relative to one another, to a second position wherein jaw members110 and 120 are closed and cooperate to grasp tissue therebetween. Eachjaw member 110, 120 includes respective electrodes 112 and 122 having anelectrically conductive tissue sealing surface, 114 and 124,respectively, disposed on an inner-facing surface thereof. Electricallyconductive tissue sealing surfaces 114 and 124 cooperate to seal tissueheld therebetween upon the application of electrosurgical energy.

Referring now to FIGS. 2A-2D, end effector assembly 100 includes jawmembers 110 and 120 connected at their respective proximal ends, 111 aand 121 a, via a suitable pivot mechanism 130. Jaw members 110 and 120are rotatable about pivot pin 132 to effect grasping and sealing oftissue 600 (see FIG. 2B). Jaw members 110 and 120 include similarcomponent features that cooperate to permit facile rotation about pivotpin 132. Other systems and methods for closing the jaws are possible andare within the purview of those skilled in the art. The jawconfiguration may also be bilateral or unilateral.

Electrodes 112 and 122 are pivotally connected to the corresponding jawmembers 110 and 120 via respective pivot mechanisms 142 and 162. Asmentioned above, each electrode 112 and 122 has an electricallyconductive tissue sealing surface 114, 124, respectively disposedthereon that are positioned to generally oppose one another, forgrasping tissue therebetween.

As shown in FIG. 2B, as jaw members 110 and 120 are moved about pivotmechanism 130 relative to one another to grasp tissue 600, electrodes112 and 122 tilt about respective pivots 142 and 162 such thatelectrically conductive tissue sealing surfaces 114 and 124 mutuallycooperate in a substantially parallel manner to engage tissue. Byassuring that the sealing surfaces 114 and 124 grasp tissue in asubstantially parallel manner, the tissue thickness between electrodes112 and 122 remains substantially uniform along the length of thesealing surfaces 114 and 124. This allows the surgeon to selectivelyapply a uniform closure pressure and a uniform amount of electrosurgicalenergy to tissue 600 between electrodes 112 and 122.

As shown in FIGS. 2C-2D, a pair of non-conductive insulating members 190are disposed on electrically conductive tissue sealing surfaces 114and/or 124 to prevent unintended shorting between the two electricallyconductive tissue sealing surfaces 114 and 124. Insulating members 190may also be used to maintain an effective gap distance between sealingsurfaces 114 and 124 to promote tissue sealing, e.g. about 0.001 inchesto about 0.006 inches. Insulating member 190 may also be configured asan insulating ridge disposed along a length of electrically conductivetissue sealing surface 114 or 124.

Referring now to FIGS. 3A-3D, in another embodiment, end effectorassembly 200 includes jaw members 210 and 220 that are connected attheir respective proximal ends, 211 a and 221 a, by a suitable pivotmechanism 230 and rotatable about pivot pin 232. The electrodes 212 and222 are configured to be wedge-shaped, such that the thickness ofelectrodes 212 and 222 increases distally along a length thereof. Anysuitable angle may be incorporated into the electrode to form thewedge-shape.

As shown in FIG. 3B, the wedge-shaped configuration of the electrodes212 and 222 promotes parallel closure of respective electricallyconductive tissue sealing surfaces 214 and 224 against tissue 600disposed between jaw members 210 and 220. As the jaw members 210 and 220move from the first position, as shown in FIGS. 3A and 3C, to the secondposition, as shown in FIGS. 3B and 3D, tissue 600 is squeezed toward thedistal ends 211 b and 221 b of jaw members 210 and 220, respectively. Atthe same time, the wedged-shaped electrodes 212 and 222 squeeze tissue600 toward the proximal ends 211 a and 221 a of jaw members 210 and 220,until tissue sealing surfaces 214 and 224 become parallel. Substantiallyparallel tissue sealing surfaces 214 and 224, as shown in FIGS. 3B and3D, ensure that tissue thickness between electrodes 212 and 222 remainssubstantially uniform along a length of sealing surfaces 214 and 224.This enables a surgeon to apply accurate closure pressure and a properamount of electrosurgical energy in a uniform fashion to seal tissue600.

FIGS. 3C-3D show a pair of non-conductive insulating members 290 aredisposed on the electrically conductive tissue sealing surfaces 214and/or 224 to prevent unintended shorting between the two tissue sealingsurfaces 214 and 224. Insulating members 290 may also be used tomaintain an effective gap distance between sealing surfaces 214 and 224to promote tissue sealing, e.g., about 0.001 inches to about 0.006inches. Insulating members 290 may also be configured as insulatingridges disposed along a length of electrically conductive tissue sealingsurface 214 and 224.

Referring now to FIGS. 4A-4D, in another embodiment, end effectorassembly 400 includes jaw members 410 and 420 pivotally connected to oneanother at proximal ends 411 a and 421 a via a suitable pivot mechanism430 including pivot pin 432. A recess 415 and 425 (see FIG. 4D) may bedefined within each jaw member 410 and 420, respectively. Electrodes 412and 422 are disposed within each respective recess 415 and 425 and arepivotally connected to respective jaw members 410 and 420 at the distalends 413 b and 423 b thereof. Alternatively, electrodes 412 and 422 maybe connected to an inner facing surface of jaw members 410 and 420,respectively, similar to that shown in FIGS. 2A-2D. Each respectiveelectrode 412 and 422 is also connected at the proximal end 413 a and423 a thereof to jaw members 412 and 422, respectively, via resilientmembers 472 and 492, such that resilient members 472 and 492 bias eachelectrode 412 and 422 against tissue 600 disposed between jaw members410 and 420. Resilient members 472 and 492 may be any compressibleand/or flexible segment as is within the purview of those skilled in theart. In embodiments, resilient members 472 and 492 are springs. As shownin FIGS. 4B and 4D, as jaw members 410 and 420 are rotated about pivotpin 432 to the second position in order to grasp tissue 600therebetween, electrodes 412 and 422 tilt about pivots 442 and 462against springs 472 and 492 to compress tissue in a more parallelmanner. As mentioned above in regards to previous embodiments, closingthe electrodes and engaging tissue in a substantially parallel mannerensures that the tissue thickness between electrodes 412 and 422 remainssubstantially uniform along a length of sealing surfaces 414 and 424,thus allowing the surgeon to apply a uniform closure pressure and auniform amount of electrosurgical energy to tissue 600 betweenelectrodes 412 and 422.

FIGS. 4C and 4D show a pair of opposing insulating members 490 disposedon electrically conductive sealing surfaces 414 and 424 configured asinsulating ridges disposed along a length of electrically conductivetissue sealing surface 414 and 424, as described above in relation toprevious embodiments. Insulating members 490 prevent unintended shortingbetween the two tissue sealing surfaces 414 and 424. Insulating members490 may also maintain an effective gap distance between sealing surfaces414 and 424 to promote tissue sealing, e.g., about 0.001 inches to about0.006 inches.

In yet another embodiment, as shown in FIGS. 5A-5D, end effectorassembly 500 includes jaw members 510 and 520 having proximal ends 511a, 521 a and distal ends 511 b, 521 b, respectively. Jaw members 510 and520 include electrodes 512 and 522, respectively, disposed on opposingsurfaces thereon. Electrodes 512 and 522 include electrically conductivesealing surfaces 514 and 524, respectively. A trapezoidal pivotmechanism 580 operably connects jaw members 510 and 520 to one anothervia pivot connections 582. Pivot connections 582 connect an actuator rod586 to trapezoidal pivot mechanism 580. When closure of jaw members 510and 520 is required, e.g., by squeezing handle assembly 40, in order tograsp tissue therebetween, actuator rod 586 is advanced distally suchthat trapezoidal pivot mechanism 580 promotes a more parallel closure ofjaw members 510 and 520, as shown in FIGS. 5C-5D. This results inparallel closure of tissue sealing surfaces 514 and 524, which ensuresthat tissue thickness between electrodes 512 and 522 remainssubstantially uniform along a length of sealing surfaces 514 and 524.The surgeon can selectively apply a uniform closure pressure and auniform amount of electrosurgical energy to tissue 600 betweenelectrodes 512 and 522.

As shown in FIGS. 5B and 5D, non-conductive insulating members 590 mayalso be disposed on electrically conductive tissue sealing surfaces 514and 524 to prevent unintended shorting between the two electricallyconductive tissue sealing surfaces 514 and 526. Insulating members 590may also maintain an effective gap distance between sealing surfaces 514and 524 to promote tissue sealing, e.g., about 0.001 inches to about0.006 inches.

Referring now to FIGS. 6A-6C, end effector assembly 601 includes jawmembers 610 and 620 pivotally connected to one another at proximal ends611 a and 621 a via a suitable pivot mechanism 630 including pivot pin632. Electrodes 612 and 622 are hingedly connected to respective jawmembers 610 and 620 at the distal ends 613 b and 623 b thereof viaresilient members 672 and 692 such that resilient members 672 and 692bias each electrode 612 and 622 against tissue 600 disposed between jawmembers 610 and 620. Resilient members 672 and 692 may be substantiallystraight or shaped pieces of spring metal or other stiff, yet bendablesegments as is within the purview of those skilled in the art to providea balanced force on tissue. As shown in FIGS. 6B and 6C, as jaw members610 and 620 are rotated about pivot pin 632 to the second position inorder to grasp tissue 600 therebetween, resilient members 672 and 692bend back with some force such that electrodes 612 and 622 tilt tocompress tissue in a more parallel manner. As mentioned above withregard to previous embodiments, closing the electrodes and engagingtissue in a substantially parallel manner ensures that the tissuethickness between electrodes 612 and 622 remains substantially uniformalong a length of sealing surfaces 614 and 624, thus allowing thesurgeon to apply a uniform closure pressure and a uniform amount ofelectrosurgical energy to tissue 600 between electrodes 612 and 622.

FIGS. 6A-6C also show optional pairs of opposing insulating members 690disposed on electrically conductive sealing surfaces 614 and 624configured as insulating ridges disposed along a length of electricallyconductive tissue sealing surface 614 and 624, as described above inrelation to previous embodiments. Insulating members 690 preventunintended shorting between the two tissue sealing surfaces 614 and 624.Insulating members 690 may also maintain an effective gap distancebetween sealing surfaces 614 and 624 to promote tissue sealing, e.g.,about 0.001 inches to about 0.006 inches.

Referring now to FIG. 7A-7C, in another embodiment, end effectorassembly 700 includes jaw members 710 and 720 pivotally connected to oneanother at proximal ends 711 a and 721 a via a suitable pivot mechanism730 including pivot pin 732. A recess 715 and 725 is defined within eachjaw member 710 and 720, respectively. Electrodes 712 and 722 aredisposed proximal to each respective recess 715 and 725 and are hingedlyconnected to respective jaw members 710 and 720 at the distal ends 713 band 723 b thereof via resilient members 772 and 792 such that resilientmembers 772 and 792 bias each electrode 712 and 722 against tissue 600disposed between jaw members 710 and 720. Resilient members 772 and 792may be substantially straight or shaped pieces of spring metal or otherstiff, yet bendable segments as is within the purview of those skilledin the art to provide a balanced force on tissue held between jawmembers 710 and 720. As shown in FIGS. 7B and 7C, as jaw members 710 and720 are rotated about pivot pin 732 to the second position in order tograsp tissue 600 therebetween, electrodes 712 and 722 tilt againstresilient members 772 and 792 to compress tissue in a more parallelmanner. As mentioned above in regards to previous embodiments, closingthe electrodes and engaging tissue in a substantially parallel mannerensures that the tissue thickness between electrodes 712 and 722 remainssubstantially uniform along a length of sealing surfaces 714 and 724,thus allowing the surgeon to apply a uniform closure pressure and auniform amount of electrosurgical energy to tissue 600 betweenelectrodes 712 and 722.

FIGS. 7A-7C also show an optional pair of opposing insulating members790 disposed on electrically conductive sealing surfaces 714 and 724configured as insulating ridges disposed along a length of electricallyconductive tissue sealing surface 714 and 724, as described above inrelation to previous embodiments. Insulating members 790 preventunintended shorting between the two tissue sealing surfaces 714 and 724.Insulating members 790 may also maintain an effective gap distancebetween sealing surfaces 614 and 624 to promote tissue sealing, e.g.,about 0.001 inches to about 0.006 inches.

While several embodiments of the disclosure have been shown in thedrawings and/or discussed herein, it is not intended that the disclosurebe limited thereto, as it is intended that the disclosure be as broad inscope as the art will allow and that the specification be read likewise.Therefore, the above description should not be construed as limiting,but merely as exemplifications of particular embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

What is claimed is:
 1. A bipolar forceps, comprising: an end effectorassembly having: opposing first and second jaw members having proximaland distal ends and selectively moveable relative to one another from afirst spaced apart position to a second position wherein the jaw memberscooperate to grasp tissue therebetween, each of the jaw membersincluding an electrode having an electrically conductive tissue sealingsurface adapted to connect to an electrical energy source such that theelectrically conductive tissue sealing surfaces are capable ofconducting energy to tissue disposed therebetween, wherein the electrodeof the first jaw member is hingedly connected to the first jaw member ata distal end of the electrode of the first jaw member by a pivot pin toprovide parallel alignment of the electrically conductive tissue sealingsurfaces when the electrically conductive tissue sealing surfaces of thejaw members engage tissue disposed between the jaw members when thefirst and second jaw members are oblique to one another, wherein theelectrode of the first jaw member is connected to the first jaw membervia a resilient member at a proximal end of the electrode.
 2. Thebipolar forceps of claim 1, wherein the electrode of the second jawmember is hingedly connected to the second jaw member to provideparallel alignment of the electrically conductive tissue sealingsurfaces when the electrically conductive tissue sealing surfaces engagetissue disposed between the jaw members.
 3. The bipolar forceps of claim1, wherein at least one of the electrically conductive tissue sealingsurfaces includes at least one insulating member disposed along a lengththereof to prevent unintended shorting between the two electricallyconductive tissue sealing surfaces when the forceps is disposed in thesecond position.
 4. The bipolar forceps of claim 1, wherein theresilient member is a piece of spring metal.
 5. The bipolar forceps ofclaim 1, wherein at least one of the jaw members defines a recesstherein for at least partially housing the resilient member.
 6. Thebipolar forceps of claim 1, wherein the electrode of the first jawmember is capable of being oblique to the first jaw member when theelectrically conductive tissue sealing surfaces engage tissue disposedbetween the jaw members.